C. Washington et al., Polymer bristles: Adsorption of low molecular weight poly(oxyethylene) - Poly(oxybutylene) diblock copolymers on a perfluorocarbon emulsion, MACROMOLEC, 33(4), 2000, pp. 1289-1297
We report the results of a small-angle neutron scattering study into the st
ructure of the adsorbed layers formed at the interface in a dilute perfluor
odecalin-in-water emulsion by five short chain diblock copolymers of oxyeth
ylene (OE) and oxybutylene (OB) (OE26OB13, OE29OB11, OE30OB7, OE27OB6, and
OE58OB13) The results are discussed in the context of the Marques-Joanny-Le
ibler scaling description of block copolymer adsorption from selective solv
ents and provide an insight into the validity of the theory in the unusual
limit of short chain lengths and small anchor blocks, close to the boundary
between the buoy-dominated and the van der Waals-buoy regimes. The volume
fraction profiles are best described by parabolic and, to a lesser extent,
Gaussian functional forms. When the temperature was increased, the buoy blo
cks were found to contract toward the surface, giving rise to profiles that
were more blocklike, in accordance with theoretical predictions by Wijmans
and Zhulina (Macromolecules 1993, 26, 7214).